To calculate a distance to a subject in an actual space, and a distance between each subject.

A distance calculation part 104c reads a photographed image from an image acquisition means 104a, recognizes a discrimination label included in the photographed image, and calculates a distance of the recognized discrimination label from a camera in the actual space, and a distance between each discrimination label in the actual space as distance information, when a plurality of discrimination labels are recognized by a recognition means.